Neuropsychological impairments in schizophrenia: Integration of performance-based and brain imaging findings

Until recently, the dominant view was that schizophrenia patients have limited, if any, neuropsychological impairments, and those that are observed are only secondary to the florid symptoms of the disorder. This view has dramatically changed. This review integrates recent evidence demonstrating the severity and profile of neuropsychological impairments in schizophrenia. We present quantitative evaluation of the literature demonstrating that the most severe impairments are apparent in episodic memory and executive control processes, evident on a background of a generalized cognitive deficit. The neuropsychological impairments potentially represent genetic liability to the disorder, as similar, yet milder, impairments are evident in schizophrenia patients even before the onset of psychotic symptoms, as well as in the nonpsychotic relatives of schizophrenia patients. Corresponding cognitive neuroimaging literature on executive functions, episodic memory, and working memory in schizophrenia documenting abnormalities in frontal and medial temporal lobes is summarized, and current models integrating neuropsychological and neuroimaging data are discussed.     

Neuropsychological Dysfunction in Children with Borderline Personality Disorder Features: A Preliminary Investigation

Borderline personality disorder (BPD) is often linked to neuropsychological deficits, yet few studies have examined BPD or its features and concomitant neuropsychological dysfunction in childhood. This study examined children with borderline features (n = 21) using the Coolidge Personality and Neuropsychological Inventory for Children and compared them to controls (n = 21) with features of at least one personality disorder, but not BPD. As hypothesized, the BPD group scored significantly higher than the control group on the Attention Deficit/Hyperactivity Disorder, Executive Functions Deficits, Mild Neurocognitive Disorder, Conduct Disorder, and Oppositional Defiant Disorder scales. It appears that behavioral disturbances associated with BPD are linked strongly with neuropsychological dysfunction. Because none of the children with BPD features in the present sample had a history of traumatic brain injury (TBI), it appears likely that TBI in the histories of adult BPD patients may not be the cause of BPD, but traits such as anger and impulsivity in BPD may cause TBI. Clinical implications and future research directions are discussed.     

Psychotic symptoms in posttraumatic stress disorder

Recent data suggest that the presence of psychotic symptoms in patients suffering from posttraumatic stress disorder (PTSD) may represent an underrecognized and unique subtype of PTSD. Among combat veterans with PTSD, 30% to 40% report auditory or visual hallucinations and/or delusions. The presence of psychotic symptoms in PTSD is associated with a more severe level of psychopathology, similar to that of chronic schizophrenia. In this review, the differential diagnosis of psychotic symptoms in PTSD is discussed, including possible comorbid schizophrenia, psychotic depression, substance-induced psychosis, and personality disorder. A recent biologic study supporting the existence of a unique subtype of PTSD with psychotic features is also addressed, as are the similarities between PTSD with psychotic features and psychotic depression disorder. Finally, data on the treatment implications of psychotic symptoms in PTSD are presented. The intriguing recent findings on psychotic symptoms in PTSD need further investigation in noncombat-related PTSD populations before findings can be generalized to all individuals with PTSD.     

A goal-striving life event and the onset of hypomanic and depressive episodes and symptoms: perspective from the behavioral approach system (BAS) dysregulation theory

On the basis of the behavioral approach system (BAS) dysregulation theory of bipolar disorder, this study examined the relation between occurrence of a BAS activation-relevant life event--goal striving--and onset of hypomanic and depressive episodes and symptoms. In particular, the authors examined the relation between preparing for and completing final exams (a goal-striving event) and onset of bipolar spectrum episodes and symptoms in college students with bipolar II disorder or cyclothymia (i.e., "soft" bipolar spectrum conditions). One hundred fifty-nine individuals with either a bipolar spectrum disorder (n=68) or no major affective psychopathology (controls; n=91) were further classified on the basis of whether they were college students (i.e., completed final exams). Consistent with the BAS dysregulation theory, preparing for and completing final exams was associated with an increase in hypomanic but not depressive episodes and symptoms in individuals with a soft bipolar spectrum diagnosis. Furthermore, self-reported BAS sensitivity moderated the presence of certain hypomanic symptoms during final exams.     

Relationships between anger, symptoms, and cognitive factors in OCD checkers

The purpose of this study was to examine whether individuals diagnosed with obsessive-compulsive disorder (OCD) with primary checking compulsions report higher levels of trait anger and anger expression compared with a student control group, and whether trait anger and anger expression are correlated with specific beliefs and interpretations that are common among individuals who compulsively check. A group of individuals with OCD reporting significant checking compulsions (n=33) and a group of undergraduate students (n=143) completed a questionnaire package that included measures of trait anger and anger expression, as well as measures of obsessive-compulsive symptoms and beliefs. The compulsive checking group reported greater trait anger, though not greater anger expression, than the student control group. Furthermore, beliefs concerning perfectionism and intolerance of uncertainty were positively correlated with anger expression and trait anger among compulsive checkers but not among the student control group. The implications of these findings are discussed in terms of cognitive-behavioural treatments for and models of compulsive checking in OCD.     

The Temporal Association Between Self‐Injurious Thoughts and Psychotic Symptoms: A Mobile Phone Assessment Study

The relationship between psychotic symptoms and self‐injurious thoughts (SITs) remains unclear. The short‐term temporal associations between psychotic symptoms and SITs were explored. A sample of 36 people with a diagnosis of a psychotic disorder or at‐risk mental state completed mobile phone‐based measures at multiple times each day for 1 week. Clustered regression with time‐lagged variables supported a relationship between paranoia and subsequent SITs. Hallucinations did not predict these thoughts when controlling for paranoia. The role of specific psychotic symptoms in triggering SITs is highlighted and the importance of considering these factors in risk management is discussed.     

Neuropsychological mediators of the links among age, chronic illness, and everyday problem solving

Reductions in everyday problem solving (EPS) are often reported in older age, although the underlying mechanisms remain unclear. The authors examined the role of 2 variables predicted to mediate (neuropsychological abilities and health status) or moderate (health status) the relationship between age and EPS performance. Toward these ends, they compared EPS and neuropsychological performance in 50 functionally independent adults with chronic kidney disease (CKD) and 64 control participants matched on age and education. Both older age and CKD were associated with worse performance on measures of EPS and memory/executive abilities. Neuropsychological abilities were positively associated with EPS performance. In both the full sample and control participants only, memory/executive functioning mediated the association between presence of chronic illness and EPS. Furthermore, memory/executive functioning partially mediated the link between age and EPS. Findings indicate that relations among age, health status, and EPS are not straightforward. Although performance on neuropsychological measures appeared to underlie EPS declines in chronic illness, increasing age remained independently associated with reduced EPS. The authors discuss implications for models of adult developmental changes in everyday cognition.     

Frontal lobe epilepsy presenting as a psychotic disorder with delusions and hallucinations: a case study

Although psychotic symptoms are a recognized manifestation of epilepsy, these are more often associated with seizures of the temporal lobe type. While 10% of children with temporal lobe epilepsy develop a psychotic disorder by adulthood, the literature does not report any cases of psychotic disorders associated with frontal lobe seizures in children. This article presents a unique case of a girl whose frontal lobe seizures were associated with delusional psychotic symptoms. Once her seizure disorder was identified through electroencephalography (EEG) and appropriate anticonvulsant therapy was initiated, her associated psychotic symptoms resolved.     

Sleep paralysis and hallucinosis

Background: Sleep paralysis is one of the many conditions of which visual hallucinations can be a part but has received relatively little attention. It can be associated with other dramatic symptoms of a psychotic nature likely to cause diagnostic uncertainty. Methods and results: These points are illustrated by the case of a young man with a severe bipolar affective disorder who independently developed terrifying visual, auditory and somatic hallucinatory episodes at sleep onset, associated with a sense of evil influence and presence. The episodes were not obviously related to his psychiatric disorder. Past diagnoses included nightmares and night terrors. Review provided no convincing evidence of various other sleep disorders nor physical conditions in which hallucinatory experiences can occur. A diagnosis of predormital isolated sleep paralysis was made and appropriate treatment recommended. Conclusions: Sleep paralysis, common in the general population, can be associated with dramatic auxiliary symptoms suggestive of a psychotic state. Less common forms are either part of the narcolepsy syndrome or (rarely) they are familial in type. Interestingly, sleep paralysis (especially breathing difficulty) features prominently in the folklore of various countries.     

Hospital-Treated Psychiatric Disorders in Adults with a Single-Parent and Two-Parent Family Background: A 28-Year Follow-up of the 1966 Northern Finland Birth Cohort

This study investigates the relationship between the family type (two-parent and 4 different single-parent types, mainly divorced) during childhood up to 14 years of age and adult hospital-treated psychiatric disorders in a sample from the unselected, general population Northern Finland 1966 Birth Cohort (N = 11,017). Up to the end of 1994, a total of 387 individuals (3.5%) had a hospital-treated psychiatric disorder, with 3.1% in two-parent families and 5.4% in single-parent families (p < .001). The single-parent family was not associated with the child's schizophrenia or other psychotic disorders. The adjusted odds ratios (OR) for personality disorders were highest among individuals without a father before the age of 14 years (OR 4.8), or at birth only (OR 4.0), or with a history of parental divorce (OR 2.8). Parental divorce was also associated with alcoholism (OR 3.7) and parental death with depressive disorders (OR 3.4). In conclusion, we found an elevated risk of hospital-treated nonpsychotic disorder among individuals from a single-parent family background. It is likely that a combination of the single-parent family and psychosocial and/or genetic risk may influence the development of these disorders.     

Memory bias in obsessive-compulsive disorder (OCD).

There is a memory bias associated with depression, and good reason to expect a memory bias associated with anxiety. However, the results of studies reported to date have been ambiguous. Accordingly, an experiment was conducted to assess memory for contamination in people with different types of anxiety. Memory for contaminated stimuli among participants who met DSM-IV criteria for obsessive-compulsive disorder (OCD) and indicated a fear of contamination (n = 10) was compared to memory in a group of anxious controls (n = 10), and in undergraduate students (n = 20). Participants were shown 50 objects, 25 of which were contaminated by the experimenter and 25 which were touched but not contaminated. They then completed a neuropsychological memory assessment, after which the participants were asked to recall all of the objects touched by the experimenter. They were then asked to approach each object and to rate their anxiety about touching it. Finally, participants were asked about their perceptions of the cleanliness of each object. The OCD group had better memory for contaminated objects than for clean ones. Neither control group showed such a bias. Neuropsychological test scores indicated that this bias is not the result of differences in general memory ability. The results are discussed in terms of the memory-deficit theory of OCD and of behavioural and cognitive approaches to understanding the role of information processing in fear and anxiety.     

A Comparison of the Neuropsychological Profiles of the DSM-IV Subtypes of ADHD

Recent research on the DSM-IV subtypes of attention-deficit/hyperactivity disorder (ADHD) has demonstrated that the subtypes differ in demographic characteristics, types of functional impairment, and profiles of comorbidity with other childhood disorders. However, little research has tested whether the subtypes differ in underlying neuropsychological deficits. This study compared the neuropsychological profiles of children without ADHD (n = 82) and children who met symptom criteria for DSM-IV Predominantly Inattentive subtype (ADHD-IA; n = 67), Predominantly Hyperactive Impulsive subtype (ADHD-HI; n = 14), and Combined subtype (ADHD-C; n = 33) in the areas of processing speed, vigilance, and inhibition. We hypothesized that children with elevations of inattention symptoms (ADHD-IA and ADHD-C) would be impaired on measures of vigilance and processing speed, whereas children with significant hyperactivity/impulsivity (ADHD-HI and ADHD-C) would be impaired on measures of inhibition. Contrary to prediction, symptoms of inattention best predicted performance on all dependent measures, and ADHD-IA and ADHD-C children had similar profiles of impairment. In contrast, children with ADHD-HI were not significantly impaired on any dependent measures once subclinical symptoms of inattention were controlled. Our results do not support distinct neuropsychological deficits in ADHD-IA and ADHD-C children, and suggest that symptoms of inattention, rather than symptoms of hyperactivity/impulsivity, are associated with neuropsychological impairment.     

An Empirical Examination of Symptom Substitution Associated With Behavior Therapy for Tourette's Disorder

Over the past six decades, behavior therapy has been a major contributor to the development of evidence-based psychotherapy treatments. However, a long-standing concern with behavior therapy among many nonbehavioral clinicians has been the potential risk for symptom substitution. Few studies have been conducted to evaluate symptom substitution in response to behavioral treatments, largely due to measurement and definitional challenges associated with treated psychiatric symptoms. Given the overt motor and vocal tics associated with Tourette’s disorder, it presents an excellent opportunity to empirically evaluate the potential risk for symptom substitution associated with behavior therapy. The present study examined the possible presence of symptom substitution using four methods: (a) the onset of new tic symptoms, (b) the occurrence of adverse events, (c) change in tic medications, and (d) worsening of co-occurring psychiatric symptoms. Two hundred twenty-eight participants with Tourette’s disorder or persistent motor or vocal tic disorders were randomly assigned to receive behavioral therapy or supportive therapy for tics. Both therapies consisted of eight sessions over 10 weeks. Results indicated that participants treated with behavior therapy were not more likely to have an onset of new tic symptoms, experience adverse events, increase tic medications, or have an exacerbation in co-occurring psychiatric symptoms relative to participants treated with supportive therapy. Further analysis suggested that the emergence of new tics was attributed with the normal waxing and waning nature of Tourette’s disorder. Findings provide empirical support to counter the long-standing concern of symptom substitution in response to behavior therapy for individuals with Tourette's disorder.     

Towards an understanding of unique and shared pathways in the psychopathophysiology of ADHD

Most attention deficit hyperactivity disorder (ADHD) research has compared cases with unaffected controls. This has led to many associations, but uncertainties about their specificity to ADHD in contrast with other disorders. We present a selective review of research, comparing ADHD with other disorders in neuropsychological, neurobiological and genetic correlates. So far, a specific pathophysiological pathway has not been identified. ADHD is probably not specifically associated with executive function deficits. It is possible, but not yet established, that ADHD symptoms may be more specifically associated with motivational abnormalities, motor organization and time perception. Recent findings indicating common genetic liabilities of ADHD and other conditions raise questions about diagnostic boundaries. In future research, the delineation of the pathophysiological mechanisms of ADHD needs to match cognitive, imaging and genetic techniques to the challenge of defining more homogenous clinical groups; multi-site collaborative projects are needed.     

Sex and age effects on the inheritance of alcohol problems: a twin study.

Male monozygotic cotwins of probands with Alcohol Abuse-Dependence (n = 85) were more likely than male same-sex dizygotic cotwins (n = 96) to report alcohol, drug, and conduct disorder problems. For women, rates of problem behavior did not differ between monozygotic (n = 44) and same-sex dizygotic (n = 43) cotwins. Opposite-sex dizygotic twin data (n = 88) revealed significant cross-sex transmission; alcohol problems were greatest among male cotwins of female probands. For men, proportion of liability variance associated with additive genetic factors was significantly greater when proband had an early (h2 = .73 +/- .18) rather than late (h2 = .30 +/- .26) age of onset. For women, heritability did not vary as a function of proband's age of onset, and the pooled estimate suggested little genetic influence (h2 = .00, SE not computable). Findings suggest that genetic influences may be substantial only in the etiology of early-onset male alcoholism.     

The diagnosis and assessment of individuals prodromal for schizophrenic psychosis

Accurate identification of individuals in the earliest symptomatic stages of psychosis offers new hope for developing more effective treatment strategies. Recently, research clinics have been set up to identify and possibly treat individuals who are seen as being at ultra-high risk of developing a psychotic disorder. This article reviews and describes measures that are currently being used and further developed in order to determine both the diagnostic criteria for the prodromal state and the severity of these putatively prodromal symptoms.     

Comparative neuropsychology of adult obsessive-compulsive disorder and attention deficit/hyperactivity disorder: Implications for a novel executive overload model of OCD

Research implicates frontostriatal pathophysiology in both attention deficit/hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). Nevertheless, ADHD is characterized with frontostriatal hypoactivity and OCD with hyperactivity. Furthermore, both disorders seem to lie on opposite ends of a clinical impulsive-compulsive continuum. While never having directly been compared, and despite these differences, OCD and ADHD appear to share similar neuropsychological impairments especially in executive functions. This study aimed at comparing adults with OCD and adults with ADHD on neuropsychological measures and behavioural impulsivity and OC measures. Thirty OCD, 30 ADHD, and 30 matched healthy control (HC) participants were administered a comprehensive neuropsychological battery and completed several questionnaires. The groups were compared on all neuropsychological and clinical measures and correlations between neuropsychological and clinical symptoms were computed. The ADHD and OCD groups performed more poorly than HC on all neuropsychological domains and most domain subtests. The ADHD group reported significantly higher impulsivity than the OCD group. OCD patients did not differ from HC on behavioural impulsivity. A unique dissociation was found between impulsivity and response inhibition where both clinical groups showed similar response inhibition deficit, but differed significantly on impulsivity. Moreover, a negative association between OC symptoms and response inhibition and a bias in self-perception of impulsivity was found only in the OCD group. We propose an executive overload model of OCD that views neuropsychological impairments in OCD as an epiphenomenon, according to which continuous attempts to control automatic processes are associated with obsessive thoughts overflow that causes an overload on the executive system.     

Childhood predictors of adolescent substance use in a longitudinal study of children with ADHD

Children diagnosed with attention-deficit/hyperactivity disorder (ADHD; n = 142) were prospectively monitored into adolescence (13-18 years old) to evaluate their risk for elevated substance use relative to same-aged adolescents without ADHD (n = 100). Probands reported higher levels of alcohol, tobacco, and illicit drug use than did controls. Group differences were apparent for alcohol symptom scores but not for alcohol or marijuana disorder diagnoses. Within probands, severity of childhood inattention symptoms predicted multiple substance use outcomes: childhood oppositional defiant disorder/conduct disorder (ODD/CD) symptoms predicted illicit drug use and CD symptoms. Persistence of ADHD and adolescent CD were each associated with elevated substance use behaviors relative to controls. Further study of the mediating mechanisms that explain risk for early substance use and abuse in children with ADHD is warranted.     

High Behavioral Approach System (BAS) sensitivity, reward responsiveness, and goal-striving predict first onset of bipolar spectrum disorders: a prospective behavioral high-risk design

A prospective, behavioral high-risk design provided a theoretically guided examination of vulnerability to first onset of bipolar spectrum disorder based on the Behavioral Approach System (BAS) model. Adolescents (ages 14-19) at an "age of risk" for bipolar disorder onset were screened on BAS sensitivity by interviewers blind to current symptoms, lifetime history, and family history of psychopathology. Participants were selected with high versus moderate levels of BAS sensitivity and administered a lifetime diagnostic interview. Those with a bipolar spectrum disorder, psychosis, or hypomanic episode with onset prior to the BAS sensitivity assessment were excluded. High BAS (n = 171) and moderate BAS (n = 119) sensitivity participants in the final sample completed baseline measures of symptoms, goal-setting, and reward responsiveness and were followed prospectively with semistructured diagnostic interviews every 6 months. Consistent with the vulnerability hypothesis of the BAS model of bipolar disorder, high BAS participants had a greater likelihood, and shorter time to onset, of bipolar spectrum disorder than moderate BAS participants across an average of 12.8 months of follow-up (12.9% vs. 4.2%), controlling for baseline depressive and hypomanic symptoms, and family history of bipolar disorder. High reward responsiveness on a behavioral task and ambitious goal-striving for popular fame and financial success (but not impulsivity) also predicted first onset of bipolar spectrum disorder controlling for the covariates and BAS risk group, and ambitious goal-striving partially mediated the BAS risk group effect. We discuss implications of the findings for the BAS model of bipolar disorder and early intervention efforts.     

The Assessment and Diagnosis of Attention Deficit Hyperactivity Disorder in Adult Forensic Psychiatric Outpatients

The primary purpose of the present study was to examine the validity of commonly utilized ADHD rating scales within an adult forensic population. Participants were 120 patients assessed for dysfunctional anger and impulsive aggression at a hospital-based clinic. Two psychiatrists made independent diagnoses about the presence or absence of ADHD among individuals presenting with symptoms consistent with this disorder. Following the diagnoses, participants were assessed with multiple ADHD measures, including measures based on self-report, observer-report, or a computerized neuropsychological measure (IVA + Plus). With the exception of the IVA + Plus, the ADHD measures significantly differentiated individuals diagnosed with ADHD from individuals who were not so diagnosed. These measures also demonstrated good diagnostic utility via test specific parameters (sensitivity, specificity, positive predictive power, and negative predictive power). A sub-set of measures demonstrated particularly good classification accuracy, with high sensitivity (91 %) and good specificity (81 %). Implications of these findings for the effective assessment and diagnosis of ADHD in adult outpatient psychiatric settings are discussed.